During an interview in which he expressed his readiness to be President of the United States, Sen. Marco Rubio (R-Fla.) rejected the science of climate change. Rubio told ABC News’ Jonathan Karl on Sunday’s “This Week” that he does not accept the findings of the National Climate Assessment which warned of the damages already occurring in Florida because of human-caused global warming. He went on to claim that “these scientists” are proposing laws to “destroy our economy.”

I do not believe that human activity is causing these dramatic changes to our climate the way these scientists are portraying it. That’s what I do not—and I do not believe that the laws that they propose we pass will do anything about it. Except it will destroy our economy.

The National Climate Assessment provides more stark evidence that climate change is happening now and threatening our health, homes, businesses and communities. It must be addressed immediately. The NCA comes only weeks after the Intergovernmental Panel on Climate Change report reaffirmed the overwhelming scientific consensus that climate change is underway and that carbon pollution from human activity is responsible for it. The message from the NCA is blunt. Without action, the damage from climate change on our communities will worsen, including: more asthma attacks and respiratory disease; threats to our food and water supplies as well as our outdoor heritage; and, more violent and deadly storms that shutter businesses and cost billions of dollars in recovery. Next month, the Environmental Protection Agency is expected to unveil an ambitious proposal to set the first-ever federal limits on carbon pollution from existing power plants — the largest U.S. contributor to climate change. We applaud the administration for its commitment to protecting our communities and our economy through the National Climate Action Plan, and call on other public officials to support the plan and these life-saving safeguards.

Sierra Club executive director Michael Brune:

Today’s landmark report is a wake-up call that we simply cannot afford to sleep through yet again. American families are already paying the costs of the extreme weather and health risks fueled by the climate crisis. Now, the nation’s most comprehensive study of climate threats shows the toll on our health, our communities, and our economy will only skyrocket across the country if we do not act. We applaud the Obama Administration for listening to these alarm bells, and urge them to continue to take critical, common-sense steps, including the first-ever limits on carbon pollution from power plants. We don’t just have an obligation to future generations to take action now—we will seize an enormous opportunity as we do. By leaving dirty fossil fuels in the ground and continuing the transition to clean energy solutions like wind and solar, we can create good American jobs and power homes and businesses nationwide without polluting our air, water, or climate.

The pipeline is intended to ship upwards of 830,000 barrels of tar-sands crude a day for a 40-year lifespan. The pipeline will add 120-200 million tons of carbon-dioxide-equivalent to the atmosphere annually, with a lifetime footprint of 6 to 8 billion tons CO2e. That’s as much greenhouse pollution as 40 to 50 average U.S. coal-fired power plants. Furthermore the Keystone XL pipeline is recognized by the tar-sands industry as a key spigot for the future development of the Alberta tar sands, which would emit 840 billion tons CO2e if fully exploited.

Interviewing Washington insiders who have offered various forms of support for the Keystone XL project, Davenport claims instead that “Keystone’s political symbolism vastly outweighs its policy substance.” To support the claim, Davenport then erroneously underestimates the global warming footprint of the pipeline by a factor of ten.
Davenport’s crucial error is to contrast the actual carbon footprint of existing fossil-fuel projects — such as US electric power plants (2.8 billion tons) and tailpipe emissions (1.9 billion) — to the impact of the pipeline’s oil being dirtier than traditional petroleum, without explaining that she was switching measurements:

Consider the numbers: In 2011, the most recent year for which comprehensive international data is available, the global economy emitted 32.6 billion metric tons of carbon [dioxide] pollution. The United States was responsible for 5.5 billion tons of that (coming in second to China, which emitted 8.7 billion tons). Within the United States, electric power plants produced 2.8 billion tons of those greenhouse gases, while vehicle tailpipe emissions from burning gasoline produced 1.9 billion tons.

By comparison, the oil that would move through the Keystone pipeline would add 18.7 million metric tons of carbon [dioxide] to the atmosphere annually, the E.P.A. estimated.

[There are two side errors in the passage: Davenport uses “tons of carbon” where she means “tons of carbon dioxide equivalent”. One ton of carbon is the equivalent of 3.67 tons of carbon dioxide. All of her numbers refer to tons of carbon dioxide-equivalent. Secondly, the estimate was not made by the E.P.A. but by a State Department contractor hired by TransCanada; the E.P.A. cited that analysis but did not make the calculations.]

What the oil-industry contractor for the State Department actually calculated is that the oil that would move through the Keystone pipeline would add 147-168 million metric tons of carbon dioxide to the atmosphere annually, 1.3 to 27.4 million of which (central estimate 18.7 million from the draft assessment) are because tar-sands crude is dirtier than other petroleum sources. Those 18.7 million tons are the “incremental” or “additional” footprint of the pipeline, not the full 160 million-ton footprint.

Based on this order-of-magnitude measurement-switching error, Davenport incorrectly concludes that “the carbon emissions produced by oil that would be moved in the Keystone pipeline would amount to less than 1 percent of United States greenhouse gas emissions, and an infinitesimal slice of the global total.”

In fact, the carbon dioxide emissions produced by oil that would be moved in this single pipeline would amount to 3 percent of U.S. greenhouse gas emissions, and half a percent of the global carbon footprint. Only thirty-two countries have larger annual footprints than this single tar-sands project.

Climate scientist John Abraham made this point in The Guardian last week. “People who think Keystone is a minor issue don’t understand science and they sure don’t understand economics,” he wrote.

Jason Bordoff

How on earth could Davenport and the pipeline supporters she cites — Michael Levi of the Council on Foreign Relations, Kevin Book of the fossil-industry consultancy ClearView Energy Partners, former Obama White House climate advisor Jason Bordoff of Columbia University’s Center on Global Energy Policy, Adele Morris of the Brookings Institution, and fossil-industry lobbyist David Goldwyn (a former advisor for Secretary of State Hillary Clinton and also a Brookings fellow) — make this basic and outsized mistake?

Putting aside any possible political and economic motivations to support the intentions of the global petroleum industry, the intellectual failure rests on an obvious error made subtle through convolution.

Whether one is looking at actual or incremental footprints of carbon-infrastructure projects, the results should be equivalent from a policy standpoint, although the numbers would be different. Why, then, does the incremental analysis used by the EPA and the State Department’s oil-industry contractors appear to give the absurd result that the Keystone XL impact is “infinitesimal”?

The methodology of incremental footprint analysis assumes a baseline of future projected carbon pollution, and then looks whether a given project would increase or decrease the baseline. The validity of incremental-footprint analysis thus depends on the baseline.

In line with scientific warnings, President Barack Obama and the U.S. State Department have committed to limiting global warming to below 2°C above pre-industrial levels. In the International Energy Agency’s 2°C scenario, global oil consumption would fall by 50 percent from current levels by 2050, within the intended operating lifetime of the Keystone XL pipeline.

The Keystone XL final environmental impact statement instead assumes that global oil demand will increase over that time period. The baseline used is the Energy Information Administration’s 2013 Annual Energy Outlook, which projects that global oil consumption will increase by 30 to 40 percent by 2040. In that scenario, the world would be on a pathway for rapid and catastrophic global warming of 4 to 6°C (or greater) by 2100.

No matter the analysis, the Keystone XL pipeline is incompatible with climate security. The global-warming impact of constructing Keystone XL is only “infinitesimal” if you assume catastrophic global warming is inevitable and that the signed climate pledges of the United States government are worthless.

Perhaps Ms. Davenport should ask Levi, Book, Bordoff, Morris, and Goldwyn if that is their assumption.

Update May 2: The Times has posted a correction:

Correction: May 2, 2014

An article and an accompanying chart on April 22 comparing the projected Keystone XL pipeline with other sources of carbon emissions referred imprecisely to projected emissions from tar-sands oil moving through the pipeline. Producing and burning that oil would emit 18.7 million more metric tons annually than would conventional oil, or far less than 1 percent of United States emissions, according to the Environmental Protection Agency. The tar-sands oil would not emit 18.7 million tons total, but about 150 million tons, or less than 3 percent of United States emissions.

The correction itself is in error; the estimate of 18.7 million metric tons is not from the E.P.A., but is from the draft assessment prepared by TransCanada contractor Environmental Resources Management for the State Department.

In a letter to the Harvard University community, president Drew Faust has announced the globally influential institution’s endowment will commit to sustainable investment practices. Harvard University has become the first educational institution to become a signatory to the United Nations’ Principles for Responsible Investment, and to the Carbon Disclosure Project’s climate program.

After increasing pressure from students, faculty, and alumni in support of the climate divestment movement, Faust reversed her previous stance opposing action, recognizing that the “special obligation and accountability to the future” held by Harvard requires action not just in research and policy but also “as a long-term investor.”

Harvard’s actions should not be interpreted as explicit acceptance of the principle that sustainable investment requires divestment from the fossil-fuel industry. However, looking at the “systemic risks presented by or created by companies” is part of the Principles of Responsible of Investment. Faust has now applied that assessment to the fossil-fuel industry, saying that the Harvard community “must devote ourselves to enabling and accelerating that transition” — “to chart the path from societies and economies fundamentally dependent on fossil fuels to a system of sustainable and renewable energy.”

Former California state senator Tony Strickland, vying for the Republican nomination to unseat Democratic Rep. Sam Farr in California’s 20th district, rejects the science of manmade global warming. Speaking at a candidate forum at the University of Southern California on Wednesday, Strickland told students that “there are a lot of scientists that say it’s a hoax.”

When I was a kid it was global cooling — I got a little older and it’s called global warming, and now it’s called climate change. The problem with that is scientists will be on both sides. There are a lot of scientists that say it’s a hoax.

In reality, the carbon-dioxide greenhouse effect is a physical fact known since the 1800s. The only scientifically plausible systematic explanation for the rapid and continuing warming of the planetary climate since 1950 is industrial greenhouse pollution. The world’s national scientific societies and the world’s practicing climate scientists are in overwhelming agreement about this fact.

Strickland’s primary opponent, former Assemblyman and USC visiting fellow Anthony Portantino, also does not seem to understand the science of global warming. “It is hotter in places where it used to be cooler and is it cooler in places where it used to be hotter,” he was quoted as saying by the USC Daily Trojan.

Portantino is incorrect. Although there are regional variations in global warming, there is almost nowhere on the planet that is cooler than it was in the middle of the 20th century.

At today’s Science Committee hearing to review the President’s proposed science budget, freshman member Rep. Randy Weber (R-Texas) dismissed climate science before expressing his support for the Keystone XL pipeline, which terminates in his district.

“You scientists start with what they call a postulate or theory and you work forward from that direction, is that right?” Weber asked White House Science Advisor John Holdren, before jesting about the science of manmade global warming.

I was wondering how that related to like, for example, global warming and eventually global cooling. I may want to get your cell phone number because if we do go through a couple of cycles, global warming and then back to global cooling, I need to know when to buy my long coat on sale. You know, so I just don’t know how y’all prove those hypotheses going back fifty, hundred, you know, what you might say is thousands or if not even millions of years and then postulate those forward.

According to Center for Responsive Politics data, Weber has received $45,000 from the energy sector in campaign contributions, the vast majority — $39,000 — coming from the oil and gas industry. Koch Industries has contributed $10,000 to his campaign coffers.

Sen. Susan Collins (R-Maine), facing reelection this year in a strongly Democratic state, has garnered the support of national environmental organizations despite a conflicted record on climate policy. In September 2013, the League of Conservation Voters launched an ad campaign praising Collins’ “environmental leadership.” A new advertisement from the Environmental Defense Fund and Moms Clean Air Force praises Collins for “confronting climate change” in marked contrast to the majority of her Republican colleagues. The organizations have not formally endorsed a candidate in the rate.

The EDF ad cites Collins’ vote on “S. Amdt 359 to SCon Res 8, Roll Call #76, 3/22/13.” That day Collins broke with the Republican caucus to vote against an amendment introduced by Sen. Jim Inhofe (R-Okla.) prohibiting further greenhouse gas regulations for the purposes of addressing climate change.

She cast a similar vote on April 6, 2011, when she broke the Republican ranks to vote against the McConnell amendment prohibiting EPA regulation of greenhouse gases.

On December 11, 2009, Collins and Sen. Maria Cantwell (D-Wash.) introduced climate legislation (S. 2877) in competition with Kerry-Boxer (S. 1733), the Senate version of the Waxman-Markey bill. Cantwell-Collins offered a simpler cap-and-trade system and weaker emissions targets than Kerry-Boxer.

However, a broader review of her voting record finds that Collins repeatedly acted to help Republicans prevent the passage of climate legislation during the Obama presidency and to weaken executive action on climate rules:

On April 1, 2009, Collins allied with Republicans and conservative Democrats in key votes to preserve the ability of Republicans to filibuster climate legislation during Obama’s first term. She voted against non-filibusterable budget reconciliation for green economy legislation, if “the Senate finds that public health, the economy and national security of the United States are jeopardized by inaction on global warming” (Roll Call Vote #125). She then voted to prohibit the use of reconciliation in the Senate for climate change legislation involving a cap and trade system (Roll Call #126. She voted for Sen. Kit Bond’s amendment establishing a point of order against climate change or similar legislation that would increase federal revenues (Roll Call #142).

These votes arguably made the future demise of climate legislation in the Senate inevitable, in contrast to health care legislation, which became law through the reconciliation process despite unified Republican opposition.

On April 6, 2011, Collins voted for Rockefeller’s bill to delay greenhouse-gas regulations for two years (Roll Call #53).

On March 21 and 22, 2013, Collins voted for Sen. Roy Blunt’s amendment to create a point of order against legislation that would create a federal tax or fee on carbon emissions (Roll Call #59) and against Sen. Whitehouse’s amendment that would support the creation of a carbon fee (Roll Call #58).

Moreover, Collins has been a consistent supporter of the Keystone XL tar sands pipeline, voting that “that no additional safety or environmental analysis of the pipeline was necessary” in 2012 (Roll Call #34) and in 2013 (Roll Call #61). Collins is also “the only member of Maine’s congressional delegation that has not called upon the State Department to do a full environmental review” of the possibility of the Portland Montreal Pipeline being used to carry tar sands crude, as the Canadian government opens the route from Alberta to Quebec for the carbon-intensive fossil fuel.

Although Collins has expressed a desire for “limiting the worst effects of climate change,” when the opportunity has come to display true climate leadership, she has supported her caucus instead more often than not.

At today’s Science Committee hearing to review the President’s proposed science budget, Rep. Bill Posey (R-Fla.) dismissed human influence on the climate. “We’ve had climate change since the day the earth was formed, whenever that was, depending on whatever it is you believe,” he said with a nod to young-earth creationists, “and we’ll have climate change until the earth implodes, whenever that is.”

Posey questioned White House Science Advisor John Holdren in depth, clearly skeptical that there could be both natural climate changes over the billions of years the earth has existed and human-induced climate change.

Obviously we’ve had global warming for a long time. You can’t have one seamless ice age that encompasses three ice ages. We had to have warming periods between each of those. And so that is a natural phenomenon. Just because we’re alive now, the tectonics plate shifts aren’t going to stop, the hurricanes tsunamis aren’t going to stop, the asteroid strikes aren’t going to stop, they’ve been going on for eons and they’re going to continue to go on for eons.

“The difference between the circumstances you’re describing and the circumstance we’re in now is the changes imposed on the climate in large part due to human activity are faster than the ability of ecosystems to adapt,” Dr. Holdren responded, “and maybe even more importantly, faster than the ability of human society to adapt.”

“There are a lot of stresses, as you point out, we can’t control, but the stresses we can control that are placing burdens on our society we ought to think about controlling,” Holdren continued.

“No doubt about that,” Posey quickly interjected before challenging Holdren on how much of present-day climate change is due to human behavior.

“The natural changes, which we understand, and which are underway on a long term basis as we speak, would be if they were the only influences, be cooling the planet rather than warming it,” Holdren replied. “We would be in a long-term cooling trend as a result of the natural forces affecting climate which we understand. We are instead in a warming trend which suggests that human activity is overwhelmingly responsible for the difference. We would be having cooling based on natural forces, we’re having warming.”

Interrupting Holdren, Posey latched on to the mention of “cooling” to make a stammering joke about global cooling and Al Gore. “I remember the ‘70s,” he said. “That was the threat, we’re going to have a cooling that’s going to eventually freeze the planet. And that was the fear before Gore intervented—invented the Internet, you know, or uh, the other terms.”

Posey, who represents the coastal Florida district that includes the Kennedy Space Center, had previously expressed similar views on ice ages and global warming in a 2011 interview with conservative activist Victoria Jackson.

A few months after the devastation of Superstorm Sandy, Rep. Thomas Massie (R-Ky.) rejected the scientific fact of anthropogenic global warming. He made remarks rejecting the linkage between human activity and changes in weather at a Heritage Foundation “Conversations with Conversatives” event on January 22, 2013. Questioned by Heritage’s Rob Bluey, Massie said he took “offense” at President Obama’s remarks on climate change in the 2013 State of the Union address.

I was disappointed to see him blame the droughts on human activity and then to say that we’re denying the evidence of scientists. As someone with a science-type background, I took offense at that. I would challenge him to show us the linkage, the undeniable linkage, between the droughts and the change in weather, and human activity.

“Now, it’s true that no single event makes a trend,” Obama said in his address. “But the fact is the twelve hottest years on record have all come in the last fifteen. Heat waves, droughts, wildfires, floods — all are now more frequent and more intense. We can choose to believe that Superstorm Sandy, and the most severe drought in decades, and the worst wildfires some states have ever seen were all just a freak coincidence. Or we can choose to believe in the overwhelming judgment of science — and act before it’s too late.”

Obama’s words were scientifically well-founded. In August 2010, the World Meteorological Organization issued a statement on the “unprecedented sequence of extreme weather events” that “matches Intergovernmental Panel on Climate Change (IPCC) projections of more frequent and more intense extreme weather events due to global warming.” Climate scientists have concluded that “[m]any lines of evidence — statistical analysis of observed data, climate modelling and physical reasoning — strongly indicate that some types of extreme event, most notably heatwaves and precipitation extremes, will greatly increase in a warming climate and have already done so.”

Massie’s “science-type background” refers to his undergraduate degree in electrical engineering and master’s degree in mechanical engineering from the Massachusetts Institute of Technology. The MIT Joint Program on the Science and Policy of Global Change has a helpful FAQ on climate science which provides answers to Rep. Massie’s questions, such as, “Are extreme events, like heat waves, droughts or floods, expected to change as the Earth’s climate changes?” The answer: “Yes.”

Massie is a freshman member of the House Committee on Science, Space, and Technology. He has received $87451 in campaign contributions from the energy industry, including $34,451 from the oil and gas industry, of which $12,000 is from Koch Industries.

If we’ve had at least three ice ages, and some people, some scientists say five, you cannot have five seamless ice ages. You must warm up between, you know, to have them. The earth has had tornadoes, hurricanes, volcanic eruptions tectonic plate shifts, meteor strikes, asteroid strikes, for millions of years, and it’s not going to stop just because we’re here now. When you think back twenty years ago, the worry was global freezing. “We’re going to freeze again. We’re going to have another ice age.”

In reality, the carbon-dioxide greenhouse effect is a physical fact known since the 1800s. The only scientifically plausible systematic explanation for the rapid and continuing warming of the planetary climate since 1950 is industrial greenhouse pollution. Paleoclimatologists have identified at least five major ice ages in the past 2.5 billion years of Earth’s history. We are currently in an interglacial period within the Quarternary or Pleistoscene ice age, defined by the permanent Antarctic ice sheet which formed 2.58 million years ago. There have been eight cycles of glaciation and retreat in the past 740,000 years. Levels of carbon dioxide and other greenhouse gases in the atmosphere due to industrial pollution are at levels not seen in the past 740,000 years, and likely not seen at any point during the current ice age. WIthout global policy to end the combustion of fossil fuels, concentrations are expected to double from current levels within decades.

Posey, elected to Congress in 2008, is a member of the House Committee on Science, Space and Technology. He has received $33,700 from the energy sector including $19,900 in lifetime political contributions from the oil and gas industry. His district includes the NASA Kennedy Space Center, Eastern Florida State College, and the Florida Institute of Technology.